w116 300sd bundt rim valve stem

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Own a 1979 300sd w116 What would cause a valve stem on an Alloy Bundt rim to be pushed in easily when tire is flat? Basically the valve stem was being held in place by the pressure in the tire.
 
Brand new valve stem, Costco tire tech said I need a new rim..Found it odd that there was no problem with the old valve stem...Provided him with an extra rim and the valve stem held its place and without air pressure.. Reason why I was at Costco was because 3 of my tires were identified as being defective. They were replaced under the warranty..
 
I'm a little unclear on the question, but rubber valves snap in. They are held in both by the air pressure (which is plenty large enough to hold them in) and the mechanical action. But I suspect, the tire tech was pointing out that the valve area on the rim was corroded. Also, when a tire is operated flat, it is not uncommon for the valve to be pulled out. The beads will wedge the valve out. Many people think it was the valve that came out first and caused the flat, but that is exactly opposite to what happened - the air was gone first.
 
Originally Posted By: CapriRacer
I'm a little unclear on the question, but rubber valves snap in. They are held in both by the air pressure (which is plenty large enough to hold them in) and the mechanical action. But I suspect, the tire tech was pointing out that the valve area on the rim was corroded. Also, when a tire is operated flat, it is not uncommon for the valve to be pulled out. The beads will wedge the valve out. Many people think it was the valve that came out first and caused the flat, but that is exactly opposite to what happened - the air was gone first.
No corrosion. Costco tire tech stated that there is only 1 standard size for valve stems. Found that comment also odd but said nothing to him. I guess the "mechanical action" failed. Is the air pressure enough to hold the valve stem in place?. Not to think of a worse case scenario where someone would kick my tire, habit, and accidentally kick a valve stem in causing a flat.. Don't mean to be joking about this but I always kick my tires...habit
 
You can't expect your neighborhood tire store to be familiar with every wheel and stem ever made. Get the stems and have them install them. Go there and tell them to fix an oddball situation without bringing a solution, may cause them to pull the plug on the entire transaction due to liability.
 
Good catch, Trav. Learn somethig new every day. And just an FYI. The holes for valves are standardized. For passenger cars, they are all the same (with the obvious exception pointed out by Trav!) They MIGHT be different for other types of vehicles. Large Earthmovers for example - but even then, they are standardized within the area. Every so often you will find some incompatibility, but it is rare.
 
I suspect they were planning a "new standard" in the nascent age of aluminum rims but it never caught on. Having six or eight wheel weight profiles, now that's smaaaaart!!!
 
Originally Posted By: Gito
Originally Posted By: Trav
good call...good info
+1 on this. I had an '81 300SD back in '02-'04 that used the same metal bolt-on valve stems on its bundt cake-style rims. I went to Sears to buy a new set of Dunlops and the installer tried to yank one of the stems off using the removal tool that is used for the usual rubber stems. Needless to say, he destroyed the valve stem and of course - they didn't have anything there that would work. Not a fun day... I think what I had to do was use the spare and order a new stem through the local parts guy that I used at the time. I think Sears paid for the stem as these normally do not need replacement - unlike rubber stems. Andrew S.
 
Originally Posted By: eljefino
I suspect they were planning a "new standard" in the nascent age of aluminum rims but it never caught on. Having six or eight wheel weight profiles, now that's smaaaaart!!!
Every so often, some one will try to carve a new path - mistakenly thinking that their thing is so much better that everyone will eventually do their way. TRX, Betamax, analog computers, left handed lug nuts, freeze dried baby food, ......
 
Originally Posted By: CapriRacer
Every so often, some one will try to carve a new path - mistakenly thinking that their thing is so much better that everyone will eventually do their way.
Point of order - analog computers pre-dated the vacuum tube (let alone the transistor) so it's not really a fair comparison. And didn't Betamax actually precede VHS? Somewhere a kid is reading this and asking 'what's VHS?' and that makes me sad.
 
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